Conventionally, a half-mold type mold package includes a substrate, an electronic component mounted on one face of the substrate, and a mold resin that is provided on the one face of the substrate and seals the one face of the substrate with the electronic component (refer to Patent Literature 1).
The substrate is formed of, for example, a resin such as a printed substrate, and has one face (also referred to as a first face) and the other face (also referred to as a second face) on respective sides of a plate. The other face, which is opposite to the one face in the substrate, is exposed from the mold resin.
The mold resin is disposed on the one face of the substrate, so as to seal a part of the one face of the substrate and expose the remaining part of the one face. The part of the one face of the substrate is provided as a sealed portion that is sealed with the mold resin. The remaining part of the one face is provided as an exposure portion that is exposed from the mold resin. This configuration is made to mount another component that is not sealed with the mold resin on the exposure portion of the one face of the substrate or to connect the substrate to the outside through a wire or the like on the exposure portion.
The inventors of the present application have found the following regarding a mold package.
With the conventional configuration, the sealed portion and the exposure portion in the substrate differ from each other in structural or physical properties, which are caused by the presence or absence of the mold resin such as thickness of the package, coefficient of linear expansion, or the like.
Due to these differences, the exposure portion has greater thermal deformation than the sealed portion in the substrate, and the difference in thermal deformation causes a stress to concentrate on a boundary between the sealed portion and the exposure portion in the substrate. In turn, this may lead to damage at the boundary, for example, a crack on the substrate, and peel-off of the mold resin.
In terms of productivity, the inventors of the present application have tried to manufacture a mold package by employing a MAP (Molded Array Packaging) molding. According to the MAP molding, multiple substrates are collectively sealed with a mold resin and then, the substrate along with the mold resin is cut into individual ones to form one package.